Taylor Swift's new song WILL make you cry

Not all of Taylor Swift's songs are about bad breakups. At Friday night's Stand Up to Cancer Telethon, she premiered a heartbreaking new ballad, dedicated to a three-year-old boy who died of cancer. "Ronan" was inspired by a blog post written by the boy's mother, Maya Thompson, who is credited as a cowriter. Watch the emotional performance below:

The singer herself got teary-eyed while sharing the true story of Ronan, who died after an eight month battle with neuroblastoma cancer. (You can read the lyrics here. If we retype them, we'll start crying too. ) Swift learned about the brave little boy through his mother's blog, Rock Star Ronan, where Thompson works to raise awareness of childhood cancer. In a blog post on Sunday, Thompson described how Taylor Swift called her out of the blue to tell her about the song:

"I wrote a song for Ronan," she said. The tears started pouring down my cheeks as soon as I heard her say those words. But her words didn’t stop there. Not only did she write a song for you, but she wanted to know if it would be alright to preform it on the nationally televised Stand Up 2 Cancer show which is on every major network and is seen in over 100 countries... She talked about how from reading this blog and following our story, has inspired her and how amazing she thinks I am and all I am doing, to bring awareness to childhood cancer.